Syt1p promotes activation of Arl1p at the late Golgi to recruit Imh1p.

In yeast, Arl3p recruits Arl1p GTPase to regulate Golgi function and structure. However, the molecular mechanism involved in regulating activation of Arl1p at the Golgi is unknown. Here, we show that Syt1p promoted activation of Arl1p and recruitment of a golgin protein, Imh1p, to the Golgi.